Up to 80% of men treated with androgen deprivation for prostate cancer suffer from hot flashes. Insomnia, fatigue, and irritability are often associated with hot flashes and adversely affect the quality of life for these patients. Several pharmacologic interventions can reduce hot flash frequency and intensity but have the potential for adverse effects. Acupuncture, a 23 centuries-old treatment modality, has been reported to substantially reduce hot flash frequency in 7 men treated with androgen deprivation for prostate cancer in Sweden. The study proposed here will apply validated methodology to assess the impact of acupuncture on hot flash frequency and intensity as well as hot flash related quality of life in an adequately powered phase Ii study. To extend current understanding of the physiologic changes associated with hot flashes and with acupuncture, the impact of acupuncture on serotonin and its metabolites, metabolites of brain norepinephrine, and circulating calcitonin gene-related peptide (CGRP) will be evaluated. All three of these systems have been implicated in the pathophysiology of thermoregulatory instability associated with hot flashes. Serotonin and norepinephrine are amongst the targets of western pharmacologic treatment for hot flashes. Preliminary data suggest that acupuncture may mediate changes in circulating serotonin and CGRP. Promising results in this pilot trial will lead to randomized studies of acupuncture compared to pharmacologic therapy and pilot studies of acupuncture combined with western treatment. The overall goal is to provide prostate cancer patients an effective, low toxicity, non-pharmacologic treatment modality for hot flashes.